Field of the Invention
This invention relates to a rotor for a rotary internal combustion engine of the kind, hereinafter referred to as being of the kind specified, in which a rotary piston or rotor, rotates within a cavity in a housing, the rotor and the wells of the cavity being so shaped that working chambers are formed therebetween which vary in volume as the rotor rotates and the cavity being provided with inlet and exhaust ports.
More particularly, but not exclusively, the invention relates to a rotor for a so-called Wankel engine in which the housing has a two-lobed epitrochoidal bore which forms the cavity and has end plates which form axially spaced end walls closing the cavity, and the rotor has an outer profile of generally equilateral triangular shape with outwardly curved sides such as convexly curved sides, and is mounted on an eccentric journal of a main shaft and is geared to rotate in a planetary manner within the cavity at one third of the speed of rotation of the main shaft.
One method of cooling the rotor of such an engine is to form one or more passageways in the rotor which form an induction passage to the working chambers so that induced air, or a proportion of induced air, is drawn through and thereby cools the rotor. Alternatively, cooling air may be forced through the passageways by an external fan or pump. An example of such an engine is shown in Canadian Pat. No. 695,953. Such engines are hereinafter referred to as having an air-cooled rotor.
If desired, fuel may be introduced into the induced air to pass through the rotor therewith and such an engine, although specifically referred to as having an air-cool rotor, is more specifically referred to hereinafter as having a charge-cooled rotor.
A problem has been encountered in high-power engines having an air-cooled or charge-cooled rotor, due to mechanical failure of the rotor when the rotor is subjected to high mechanical and thermal stresses, which are commonly imposed during high speed and high load running, for a long period of time.
Accordingly objects of the invention are to provide a new and improved rotor for a rotary engine of the type specified and a new and improved engine, wherein the above mentioned problem is overcome or is reduced.